<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        .c1{
            color: red;
        }
        #c2{
            color: gold;
        }
        li{
            color: aqua;
        }
        input[type='text']{
            border: 5px solid pink;
        }
        .v1[xx='111']{
            color: aquamarine;
        }
        .yyy > a{
            color: blueviolet;
        }
    </style>
</head>
<body>

    <div class="c1">中国</div>
    <div id="c2">河北</div>
    <div>石家庄</div>

    <ul>
        <li>哈哈</li>
        <li>咔咔</li>
        <li>咯咯</li>
    </ul>

    <input type="text">
    <input type="password">

    <div class="v1" xx="111">x1</div>
    <div class="v1" xx="222">x2</div>
    <div class="v1" xx="333">x3</div>

    <div class="yyy">
        <a>百度</a>
        <div>
            <a>阿里</a>
        </div>
    </div>

</body>
</html>